CO Down property developer John Miskelly always believed he'd been wronged when his business empire - including Ten Square hotel in Belfast city centre - was forced into administration by Cerberus in 2014.

He had bought the popular boutique hotel from the Hill brothers (they also owned the Galgorm Resort) for a reported £10 million in 2008.

In those days of largesse, just before the crash, Miskelly had a property empire across Britain and Ireland thought to be worth more than £65m.

But by the time Nama and then Cerberus moved in, Miskelly - who was once touted as a prospective buyer of Liverpool Football Club - was said to be in hock to creditors to the tune of £4m.

However, the 52-year-old Ballynahinch man - who was recorded by the BBC allegedly making a £40,000 payment to businessman Frank Cushnahan in a hospital car park in 2012 at a time when the latter was still working as an adviser to Nama - always feared there was a culture of cronyism at work, so probably felt he needed to 'cover his back'.

And he now claims he has detailed evidence of Northern Irish property dealings that occurred since the 2008 financial crisis that were tainted by financial misconduct and corruption.

Video courtesy of BBC Spotlight:

The Spotlight programme is available on the BBC iPlayer bbc.co.uk/iplayer

Much of that event was garnered, it seems, through surreptitious recordings he made during a series of meetings in which he attended.

Miskelly has subsequently turned whistle-blower, informing the American financial watchdog, the Securities and Exchange Commission (SEC) of alleged wrong-doing.

He has also passed his hours of recordings to the National Crime Agency (NCA), which heads the UK’s law enforcement battle against serious and organised crime.

In one of Miskelly's secret tapes, revealed on the BBC this week, he is also heard saying that Gareth Robinson, son of Northern Ireland’s former First Minister Peter Robinson, told him to get in touch with Frank Cushnahan for advice.

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In a statement in the wake of the latest Spotlight programme, Miskelly said: "Since 2007/8 I have consistently and truthfully reported financial crime and corruption with the relevant authorities.

"My overriding aim has always been to highlight wrongdoing and corruption and have all of these matters fully investigated by the appropriate authorities.

"I have at all time made clear, that payments made by me to any persons have been lawful and legitimate.

"As a witness I am participating in the ongoing investigations by the NCA and authorities in the United States and in the interest of integrity of the judicial process I am unable to make any further comment."

This latest twist in the long-running saga of alleged corruption at the heart of the biggest-ever property deal in Northern Ireland - where the cast of players, both central and peripheral, encompasses senior politicians, businessmen, bankers and even former US vice-president Dan Quayle - will only fuel fresh demands for a broad-ranging investigation into the £1 billion sale.

And, remember, amidst all the mud-slinging, claims and counter-claims, it's ultimately the Northern Ireland tax-payer who is a loser in all this, because when Nama sold its portfolio to Cerberus, it did so at a loss of more than £150 million.